During surgery on the human body, it is essential that organs or passages, such as the urethra and ureter, not be cut. The presence of blood, sponges, intervening tissue and the like make it extremely difficult to locate with great accuracy such organs or passages in the vicinity and particularly immediate vicinity of the region on which surgery is being performed.
Light emitting catheters are used to detect irregularities in a duct, vessel, organ or the like. U.S. Pat. No. 4,248,214 provides an illuminated urethral catheter to assist a surgeon in locating the junction of the bladder and the urethra to permit the proper performance of the Marshall-Marchetti-Kranz procedure. U.S. Pat. No. 4,782,819 is representative of many patents using catheters for illuminating organs for internal inspection.
The use of infrared sensors internally of the body to locate heat generating body tissue, such as cancers, is disclosed in several patents, for instance, U.S. Pat. No. 4,784,128. U.S. Pat. No. 4,821,731 uses a sound generating catheter to image internal features of the body.
None of the references cited disclose the concept of employing an infrared generating catheter and infrared detector for the purpose of defining the location of the passage, organ, etc. so as to permit a surgeon working in the region to have a clear knowledge of the location of the region to be avoided.